This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Cocaine and amphetamine regulated transcript (CART) is a putative neurotransmitter, originally found to be upregulated by in the nucleus accumbens by psychomotor stimulants. Various studies demonstrated CART to have psychoactive properties and to be involved in the actions of cocaine and dopamine in multiple nuclei. Therefore, understanding the anatomy and physiology of CART neurons is important in dissecting the phenomenon of drug abuse and addiction. The overall purpose of this project is to elucidate the relationship between CART and drugs of abuse such as cocaine and amphetamine. Our lab used immunocytochemistry in conjunction with confocal fluorescence microscopy to determine that cocaine activates CART neurons in the nucleus accumbens, thought to be a major anatomical center for drug abuse and reward. We used an anterograde neuronal tracer to show that CART neurons project from the nucleus accumbens to the ventral pallidum. This data was confirmed using a retrograde tracer injected into the pallidum that retrogradely labels neurons originating in the nucleus accumbens. Additionally, immunocytochemistry at the electron microscope level was used to describe the synapses of CART-containing neurons in the ventral pallidum.